import numpy as np
import matplotlib.pyplot as plt
x=np.random.rand(50)
y=np.random.rand(50)
area=np.pi*(15*np.random.rand(50))**2
color=2*np.pi*np.random.rand(50)
plt.scatter(x,y,s=area,c=color,alpha=0.5,cmap=plt.cm.hsv)
plt.show()
